Naming: Why should named constants be all uppercase in C++/Java?

Question

I know, that for C++ and Java it is a well established naming convention, that constants should be written all uppercase, with underscores to separate words. Like this (Java

Answer 1

I believe in C++ it's a convention carried over from the days of using the preprocessor to #define constant values. Back then, it was done to avoid having the preprocessor trample all over your source code, as the usual conventions for C function and variable names would make them mixed case or lower case.

From a C++ point of view, I would say that it's a bad idea to make your constants all-uppercase. I've had to debug more than one build problem because of this - remember that the C++ preprocessor does know nothing about namespaces and naming scope and will happily substitute what it thinks is appropriate even though it is rather inappropriate.